Sanding tools, such as random orbit sanders, are frequently powered by a pneumatic compressed air supply. Pneumatically powered sanders can be designed to create a self-generated vacuum to capture dust and debris by sending the exhaust air from the pneumatic motor through a venturi in the exhaust air stream to create a suction port. The suction is directed with shielding and porting to the surface of the work piece through utilization of a ventilated abrasive article and back-up pad having a plurality of dust transport holes. The dust laden air stream after the venturi can be directed to a dust capture bag that is attached to the exhaust port (dust exit port) of the sander.
Typically, a cloth or paper capture bag is attached to a vacuum hose connected to the dust exit port, or the bag is attached to the dust exit port directly to filter the exhaust air and to capture the sanding dust and debris. While the cloth dust bag functions to capture some of the dust, frequently very fine particles of dust are not retained inside the cloth dust bag. Additionally, depending on the type and size distribution of the sanding dust, the pores in the cloth bag can be quickly plugged greatly reducing the efficiency of the bag to collect further dust and debris. Once plugged up, the cloth dust bag must be removed, emptied, and cleaned of the residual dust before sanding can continue. Furthermore, once the dust is collected within the cloth bag, the dust can shift in the bag causing a reduction in the ability of the cloth bag to capture further dust. For example, when sanding on a vertical surface the captured dust within the cloth bag may partially block or obstruct the entry port into the cloth bag depending on the orientation of the cloth bag with respect to the force of gravity.